Thank you for the reply.
I've got some tidal experience this February and April in Solent. Guess, this will help.
Did you anchor at Ille de Houat? If I got it right the only harbour there to moor is Saint Gildas which seems too shallow for our 2.4m draught.
I do want to plan two nights stay at Belle Ille - but probably we won't make it there on the first day. Our check-in time is 1400 at La Trinite, 16 Nm to Le Palais, and with opening time 1h30 before HT to 1h after HT we could really miss the gate - if HT on Sept 29 is to early. Today Sept 4 it's at 1647 and 1900. So, considering HT is about 50 min later every day on Sep 29 it'll be around 0300 and 1500 - got no almanac to check it now. What would you suggest for the first day passage in that case?
At I. de Houat we tied up to a corps mort
(huge concrete anchor in most of these ports) - expect to raft up with others. I can't remember our draft but it was a Sunfast 37, so probably 1.7m.
You might just go for a sail in the ocean and then enter the Golfe de Morbihan for your first night -- it is right next to Trinité. We grabbed a buoy for the night somewhere close to Vannes.
Another possibility -- it is about 35nm from Trinité to l'Orient. From Google Earth it looks like there are multiple marina possibilities. I don't think a river entrance like this will have a threshold at the mouth but I am not sure since I don't have a guide to ports handy.
If you have part of a day on Belle Ile, visit the lighthouse - the view is spectacular.